Home-made air filter system

[THyman]

I have a used 2 speed furnace squirrel-cage fan that I want to use for a air fitler system and I have a question about whether to mount it horizontal or vertical (the blade axis that is)? If I mount it vertically, I can use a 16x25 filter and there will be about 2-3 inches of clearance between the top and bottom of the box and the fan. If I mount if horizontally, I will have to use 20x20 filters and there will be 3-4 inches of clearance between the side of the box and the fan. To mount the fan (this is one heavy fan) I will probably mount the fan by using longer srews (3) that mount the motor to the blade shaft. The fan does have a metal flange on the exhaust side, but it is only 1/2 inch wide and I don't think that it would hold the weight of the fan. What to you guys think. Thanks for you assistance.

[siliconbauhaus]

The home made fan I saw in shopnotes ( I think ) was mounted in the upright position ( making he blade axis horizontal ).

[Salty]

The air exiting out of the fan is what they call 'cohesive air'. Meaning that it runs in a straight line as opposed to an axial fan that forms a kind of funnel shape. So, either way would be the same where the exhaust is concerned. The question then becomes how the orientation of the inlet suits your setup.

[eezlock]

fan...

It probably would not make any difference which way you mount the fan
to use in the shop. The main thing is don't restrict the inlet/ outlet
area of the fan so that it can do it's job. I have one that came from a HVAC
dealer/friend of mine, I built a wooden enclosure around it, made filter racks
(2) of them one on each side, cut approiate opening in shop outer wall and mounted to the shopwall, wired up switch and let her rip! On the outside
of the wall, I installed a sliding vent cover over it to keep bugs, birds,
and other little varmints from entering the shop thru the fan housing, and it works well. eezlock

[WayneJ]

You might want to think about the bearing load on the motor. Most motors are made to be operated in the horizontal position. Verticaly it would need a thrust bearing to support the weight of the fan assy. You might want to check to see if your motor would handle that type of load.
Wayne

[Slik Geek]

I have a used 2 speed furnace squirrel-cage fan that I want to use for a air fitler system.

Just don't make the same mistake that I did. Use high quality, high performance filters.

(And WayneJ makes a great point about the bearing load).